By Yereth Rosen

ANCHORAGE (Reuters) - Alaska is planning to sue BP Plc to recover "several hundred million dollars" in oil revenues it says it lost when the company partially shut down the giant Prudhoe Bay oil field because of pipeline leaks in 2006, state officials said Friday.

Alaska "estimated the number of barrels of oil not produced due to shutdowns or reduced production due to corrosion of pipelines and it was tens of millions of barrels," Assistant Attorney General Steve Mulder said.

"The state's revenue off those barrels in 2006 and 2007 would have been in the hundreds of millions of dollars."

The state continues to seek a negotiated settlement with BP over its claims, but the suit would be filed by the end of the year, if talks fail, Mulder said.

Alaska lawmakers have inserted a $4.7 million appropriation into the state's proposed fiscal 2009 budget on Thursday to pay for outside experts to assist in the lawsuit.

Corroded oil transit pipelines at Prudhoe Bay led to a major spill in March 2006 and the partial shutdown of the field in August of that year.

A federal investigation concluded BP had failed to adequately maintain the pipelines and blamed a cost-cutting mentality at the company for the incidents.

BP pleaded guilty to a misdemeanor environmental crime in November and paid $20 million in fines to settle all federal and state criminal investigations into the corrosion problems.